Grinding-machine.



A. B. JERRAM.

GRINDING MAGHINE.

APPLICATION FILED SEPT. 21, 191 2.

Patented Feb. 9, 1915.

3 SHEETS-SHEET 1.

paw My I I A. E. JBRRAM.

GRINDING MACHINE. APPLICATION FILED SEPT 21. 1912.

1,127,443, Patented Fm, 1915.

3 SHEETS-SHEET a.

the tooth to cut.

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ARTHUR ERNEST JEBRAM, OF LEICESTER, ENGLAND, ASSIGNOR T0 UNITED SHOE MACHINERY COMPANY, OF PATERSON, NEW JERSEY, A CORPORATION OF NEW JERSEY.

GRINDING-MACHINE.

Specification of Letters Patent.

Patented Feb. 9, 1915.

Application filed September 21, 1912. Serial No. 721,524.

To aZZ whom it may concern:

Be it known that I, ARTHUR E. JERRAM, a subject of the King of England, residing at Leicester, Leicestershire, England, have invented certain Improvements in Grindingl\lachines, of which the following description, in connection with the accompanying drawings, is a specification, like reference characters on the drawings indicating like parts in the several fig This invention relates to grinding machines and is illustrated in connection with a machine for grinding the teeth of rotary cutters used in trimming the edges of the soles of boots and shoes. Cutters used for this purpose are circular in outline with a plurality of evenly spaced teeth, the ends of which are shaped to correspondto the shape to which it is desired to trlm the sole edge, and each tooth is backed off at a slight angle to its direction of motion to give the clearance necessary to enable If, when grinding or sharpening these cutters, the amounts removed from the faces of the teeth are not uniform, the diametrical length of the teeth will vary correspondingly, and the true periphery of the cutter edge will not be maintained. In practice cutters thus incorrectly ground vibrate when in contact with the work and do not produce smooth edges.

The general object of the present invention is to overcome this defect and to produce a device which will correctly space the teeth automatically and grind them rapidly and accurately.

To this end one feature of the present invention consists in the combination with a grinding member of a support for a mat ter, means for imparting relative movement to said member and support to cause the cutter to be brought into and out of contact with said member, and novel means for moving the cutter angularly while it is out of contact with said member.

In order to produce a compact machine, another feature of the invention consists in the provision in a machine of this type wherein relative movement takes place between the grinding member and the support for the cutter of novel means operated by this movement for imparting the angular movement to the cutter.

In order to prevent a tooth from being ground a second time and to insure that the same amount of material shall be removed from all the teeth, another feature of the invention consists in the provision in a machine of the class described having mechanism for presenting the teeth of a cutter one by one to a grinding member of means for bringing said mechanism to rest when the last tooth has been ground.

These and other features of the invention including certain details of construction and combinations of parts will be described in connection with an illustrative machine and pointed out in the appended claims.

Referring now to the accompanying drawings,Figure 1 is a front elevation of a portion of a machine in which the present invention is embodied, the grinding wheel having been omitted and certain parts shown in section; Fig. 2 is an end elevation of the machine; Fig. 3 is a plan of certain portions of the machine; Fig. 4 is an enlarged sectional view of a portion of the cutter carrier, a cutter being shown in place, and Fig. 5 is a detail of a portion of the mechanism which automatically stops the machine."

The illustrative machine comprises a 7 frame 1 having bearings 2 in which is mounted so as to rotate a shaft 3. The shaft 3 is provided with a driving pulle 4 and a loose or idle pulley 5, the said sha t being driven by means of a belt not shown. To the frame 1 is bolted a projecting portion 6 in which is mounted a fixed spindle 7. Pivoted on the spindle 7 is a lever 8, the upper portion of which is forked and is provided with bearings 9. In these bearings is rotatably mounted a shaft 10 to which is secured a frame 11 that carries a cutter 12 as will be described later.

The lever 8 is arranged so that it can be moved about the spindle 7 in order to swing the frame 11, and consequently the cutter mounted thereon, toward or from a grind ing wheel 13, mounted on the shaft 3,'in order to vary the inter-meshing of the grinding wheel and the cutter so as to suit different forms of teeth and cutters, or difierent diameters of cutters and grinding wheels.

The mechanism for carrying this into effect comprises a rod 14 one end of which is screwed into a stud l5 rotatable in the provided with a reduced portion which passes through a rotatable stud 16 supported in a forked portion'of the lever 8. A milled headednut 17 is secured to the rod 14, and it will be seen from the foregoing'that when the said nut is turned in one or the other direction the rod 14 will be rotated and the lever 8 will be swung about the spindle 7 and the cutter 12 moved nearer to or farther away from the grinding wheel as just mentioned.

The frame 11, which for the sake of convenience will be referred to as the cuttercarrying frame, is provided with mechanism so arranged that it, tind consequently the cutter mounted thereon, can be swung upwardly and downwardly about the axis of the shaft 10 so that a tooth of the cutter 12 shall be drawn across the grinding wheel 13 and thus be ground. The shaft 10 is parallel to the shaft 3, and the frame 11 is so arranged and operated as to carry the cutter 1I1L0 or across the plane common to the two shafts, as clearly shown in Fig. 2. The mechanism for carrying this into effect comprises a shaft 18 which is mountedso as to be capable of rotation in a bearing 19 formed in the extension 6. On one end of this shaft is formed a crank 20 to which is pivoted at 21 a link 22, the said link being pivoted to the frame 11 at 23. The shaft 18 is adapted to be clutched to a gear Wheel 24, which is mounted loosely on the said shaft. This clutch comprises a sleeve 25 surrounding the said shaft 18 and arranged to slide endwise thereon and carrying a pin 26 which projects through a slot in the said shaft so that the sleeve is splined thereto. The sleeve 25 is provided with a second pin 27 which is adapted to enter a socket in the gear wheel 24 and thus lock the, shaft 18, sleeve 25 and gear wheel 24 together so that when the said gear wheel is rotated by mechanism which will be described later, the shaft .and its crank will also be rotated, and the carrier 11 and consequently the cutter 12 be moved upwardly and downwardly, f

In order to hold the pin 27 firmly in its socket a spring 28 is provided which is located within the hollow end of the shaft 18 and held in place by means of a screw 29. This spring bears on the pin 26 and 3 tends to move the sleeve 25 along the shaft and so hold the pin 27 firmly in its socket.

A hand wheel 30 is provided on the end of In order to rotate the gear wheel 24, the machine is provided with a shaft 31, mounted in bearings in the frame, carrying a worm wheel 32, which meshes with the gear wheel 24, and a gear wheel 33, which meshes with a worm wheel 34 on the shaft The cutter 12 is supported by a spindle 35 that is mounted for rotation in a boss in the frame 11 in such a position that the plane of the cutter will be transverse and substantially at right angles to the directions of oscillation of the frame, as clearly shown in the drawings. This spindle is provided with an enlarged head portion 36 having a slot formed therein in which are pivotally mounted the members 37. The members 37' are provided with undercut portions 38, and the said members are normally held away from each other by means of a spring 39. It will be seen that in order to place the cutter in position upon the spindle it is only necessary to slide it over the members 37 which will yield toward each other for this purpose, until the cutter rests upon a flange formed on the head of said spindle, see F ig. 4. The flange is provided with a projection 41, for a purpose which will be described later, which, when the said cutter is resting on the said flange, projects between two teeth of the cutter. When the cutter has been slid over the locking members or catches 37 :in the manner just stated the said members are separated by the spring 39 so that their undercut portions 38 bear on the top of the cutter and thus hold it firmly in position upon the spindle 35.

In order to give a step by step motion to the cutter 12, so that'each tooth in turn can be ground, the following mechanism is employed. A cutter-rotating pawl 43, one face of which is adapted to contact with the tooth that is being ground (for example the tooth 45, see Fig. 3) but against its rear face is'pivoted at 47 to a bent lever 49 the other end of which is'mounted so as to be capable of partial rotation on a pin 50 that is mounted in the frame 11 by means of a nut 51 and a washer 52. The lever 49 is provided with a cam roll 53 which is adapted to contact with a fixed cam 54 mounted on one of thebearings 9 when the cutter-carrying frame 11 and consequently the lever 49 pivoted thereto are moved upwardly by the crank 22 and mechanism previously described. The cam 54 will move the lever 49 about the pin 50 and cause the pawl 43-by means of the tooth 45 with which it contacts on the upward movement to rotatev the said cutter forwardly an amount equal to the distance between two ment of the frame 11 the said cam roll 53 is held against the cam 54, the lever 49 is returned to its normal position, and the pawl drawn backward over the tooth 55, by the actionof a springpressed plunger 56 which bears against the frame 11. In order to prevent backward movement of the cutter as the cutter-rotating pawl 43 is drawn backward over the tooth 55 a second or positioning pawl 57 is provided which is pivoted at 58 to thecutter-carrying frame 11 and operated upon by a spring 59 so that it will slide over the tooth to be ground as this is moved forward, but just before the cutter-rotating pawl 43 is drawn backward will be moved into position by said spring 59 behind the tooth, and form an abutment for the face of the tooth opposite to that which is to be ground.

A spring 60 is provided which bears against the cutter-rotating pawl 43 and serves the purpose, not only of keeping the pawl against its tooth, but also on the return stroke',-z'. 6., after moving forward the cutter, causes the said pawl to bear against the leading face of the next tooth to be ground and moves the cutter yieldingly backward so as to insure that the next tooth to be ground shall be pressed firmly against the positioning pawl 57. This mechanism insures-that the cutter shall be advanced'the correct amount.

The pawl 43 is provided with a. handle 61 so that it can be moved by hand out of its operative position when desired.-

On the lever 49 an adjustable stop 63 is provided in the form of a bolt screwed into the lever and locked in place by a nut 64. The stop 63 is so located as to abut against the bearing of the frame 11 when the lever has completed its return motion. It will be seen that by turning the stop 63 in one or the other direction the length of the stroke of the lever 49 and consequently the cutterrctating pawl carried thereby will be varied so that the distance through which the cutter is moved may be varied to accommodate cutters which difier from one another as to their number of teeth. For edge-trimming cutters in which the number of teeth varies very little, theoverstroke of the cutter-rotating pawl automatically takes care of cutters with varying numbers of teeth.

From the foregoing it will be understood that it is only necessary for the frame 11 to be swung upwardly and downwardly a given number of times in order to advance each tooth in turn into a position in readiness to be ground and l in order to move each tooth across the grin ing wheel.

In order to stop ,the machine automatically when all the teeth of the cutter have been ground the following mechanism is employed. A detent 65 and a tappet 67 are secured to a shaft 69 that is rotatably Y mounted in a bearing 71 formed in an arm 73 rising from the frame of the machine.

The detent 65 is arranged so that it lies normally in the path of a belt-shifting lever 75, which is pivoted to the frame of the ma chine at 76, when the latter is in its inoperative position, that is, when it is in a position in which it has shifted the belt on to the idle pulley 5. When, however, the lever 75 is moved from its inoperative toits operative position, that is, when it has shifted the belt on to the driving pulley 4, the detent 65 will be pushed on one side by the said lever until the lever reaches the position shown in Fig. 1, when the detent 65 under the action of gravity will swingbebind the said lever and hold it in its opera- .tive position, a projecting portion 77 being formed on the detent 65 which contacts with the said lever for this purpose. The lever 75 is acted on by a spring-pressed plunger 78 which swings the said lever into its inoperative p .vsition when the detent 65 is moved away from the said lever. The detent. 65 is moved away from-the lever 75 automatically when all the teeth of the cutter have been ground so that the machine is stopped at this time.

In order to move the detent 65 at this time a cam plate 79 is provided, which is pivotally mounted on the washer 52 which surrounds the pin 50 and is held in place by the nut 51, and a'plate 81 secured to the frame 11 by screws acts as a guide for the said cam plate. A spring 82, one end of which is secured to the frame 11 and the other end to the cam plate 79, is provided which tends to move the said cam plate about the axis of the pin 50. The plate 79 is provided with a claw 83 which bears against the periphery of the spindle 35 and prevents the said movement of the plate until the claw encounters a groove 84 formed in the said spindle 35 when the said claw will be moved into the said groove by the spring 82 and the plate moved about the axis of the pin 50. This will cause the plate 7 9 to project forward slightly so that, when the frame and cutter aremoved upwardly, it will contact with the tappet 67 and cause the shaft 69 to be swung in its bearing 71 and thus move the detent 65 in a direction toward an observer viewing Fig. 1. This movement of the detent 65 swings it clear of the lever 75 and allows the said lever under the action of its spring-pressed plunger 78 to move into its inoperative positionand thus stop the machine. The tappet 67 is provided with a handle 85 so that the said detent 65 can be released manually from the lever-7 5 and the machinestopped at any desired time. The lever 75 isprovidedwith a brake surface 86 formed on a lever 87 which is pivoted at 88' to an extension on the lever 7 5,, and this brake surface is adapted to contact with the face of the driving pulley 4 when the lever is moved under the action of its spring pressed plunger 78 into its inoperative position and thus stop the machine. The lever 87 is adapted to be moved about its pivot 88 so as to vary the pressure which it will exert on the driving pulley 4, and this adjustment is carried out by means of a bolt 89 which is screwed into the lever 75 and provided with an annular groove which receives the forked upper portion of the lever 87. The lever 75 isprovided with a forked portion at its lower end which engages-a pin 90 fixed to the frame of the machine so as to limit its movement about its pivot 76 in either direction.

The method of operation of the machine may briefly be summarized as follows :-The cutter to be ground having been mounted on the spindle 35 in the manner priviously described, the said spindle is tu :ned into a position so that the claw 83 is in the position P indicated in Figs. 3 and 5, that LS, just clear of the groove 84. The lever 7 5 is swung into the position indicated in Fig. 1. and the ma- 5 chine thus started up. The frame 11 and the cutter 112 will then be swung upwardly by the crank 20 operated by the mechanism described, and the lever 49 will be moved about the spindle 50 by the stationary ;cam 54 contacting with the roll 53. This movement will cause the cutter-rotating pawl 43 to move the cutter a distance equal to the distance between two teeth, and consequently a new tooth will be brought into a position in readiness to be ground. Ow-

ing to the projection 41 on the flange of the shaft 35 (see Fig. 4) it will be seen that as the cutter is'rotated the spindle 35 will also be rotated so that the groove 84 will 40 be gradually moved away from the claw 83.

On the downward motion of the frame 11 the tooth which has just been moved into its position in readiness to be ground will be drawn across the grinding wheel 13 and thus the tooth will be ground. The reverse motion of the lever 49 to that caused by the cam 54, as previously pointed out, is produced by the spring-pressed plunger 56. This upward and downward movement of 50 the cutter is repeated until-the cutter and consequently the spindle 35 has made one complete revolution, and at this time the groove 84 will have come opposite to the claw 83 which will be moved into said groove by the spring 82 and causethe cam plate 7 9 to project forwardly an amount such that during the next upward movement of the frame it will contact with the tappet 67.

and conseguentlv move the detent away to from the lever 75 and allow the said lever under the action of its spring-pressed plunger 78 to be moved into its inoperative position and thus stop the machine. n

While the pawl 43 is rotatin the cutter 65 forward the positioning pawl 5 will slide over the tooth which is next to be ground and will take up a position behind the said tooth and form an abutment for the tooth while it is being ground. As previously mentioned the spring 60 acting on the cutter-carrying pawl 43 will, while the said pawl is being drawn over the tooth next to be ground, move the cutter yieldingly backward and thus press it firmly against the positioning pawl 57.

In order to regulate the amount to .be ground from each tooth the shaft '3 is made.

adjustable endwise by means of a screwed bush 91 which is screwed into the bearing 2 and is provided with a hand wheel 92 so that when the said bush is turned in one or the other'direction itwill move the shaft 3 bodily, the said shaft being held to move longitudinally with the bush and being splined to the gear 34 and pulley 4 for this urpose. Although the invention has beenset forth in connection with a particular machine, it

should be understood that the invention is not limited in the scope of its application to the particular machine shown and described.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. A' machine .of the class described having, in combination, a grinding member, a

member for supporting a toothed cutter, one of said members being movable to effect alternate engagement and disengagement of the grinding member and the cutter, said supporting member being constructed and arranged to maintain the cutter with its tooth to be ground in the same angular relation to the grin-ding member, during the support for'a toothed cutter, said support being movable to carry the cutterinto and out of contact with the grinding member,

and arranged to maintain the cutter with its tooth to be ground in the same angular relation to the grinding member during the grinding operation, and means for moving the cutter angularly while it is out of contact with the grinding member comprising a lever pivoted upon the cutter support, resilient means for positioning the lever normally with reference to the support, and

positive means for moving the lever in a direction to advance the cutter angularly upon ainovement of the supportin a direc- 3. A machine of the class deslcribed having, in combination, a grinding member, a support for a toothed cutter, said support being mounted for oscillatory movement about an axis extending transversely to the plane of the grinding face of said member to cause the teeth of the cutter to be brought into and out of contact with said face, and means for imparting intermittent angular movement to the cutter to bring the teeth successively into position to be ground comprising a lever pivoted on the cutter support and a cam constructedand arranged to move the lever in a direction] to advance the cutter upon a movement of the support in a direction to carry the cutter out of contact with the grinding member.

4. A machine of the class described having, in combination, a grinding member, a

support for a toothed cutter, said support being mounted for oscillatory movement about an axis extendin transversely to the plane of the grinding %ace of saidmember to cause the teeth of the cutter to be brought into and out of contact with the grinding member, and means for imparting intermittent angular movement to the cutter to bring the teeth successively into position to be ground comprising a lever pivoted on the cutter support, a pawl on the lever for engaging the teeth of the cutter, and means for moving the lever in a direction to efi ect angular movement of the cutter upon a movement of the support in a direction to withdraw the cutter from the grinding member.

5; A machine of the class described having, in combination, a grinding member, a member for supporting a cutter, one .of said members being mounted for oscillatory movement to effect alternate engagement and disengagement of the grinding member and the cutter, and a support for said oscillatory member mounted for swinging movement to adjust theposition of the axis of oscillation of said member.

' 6. A machine of the class described having, in combination, a rotary grinding member, a support for a cutter, means for swinging said support about an axis substantially parallel to the axis of said grinding memher to move the cutter into and out of conof contact with said member, and means including a lever pivotally mounted on said support and operated bythe swinging movement thereof for moving said cutter angularly while the cutter is moving in a direction away from said member.

8. A machine of the class described hav- .ing, in combination, a grinding member, a

support for a toothed cutter, means for imparting relative movement to said member and support to cause the cutter to be brought into and out of contact with said member, and means for rotating the cutter first forwardly and thenbackwardly while said cutter is out of contact with said grinding member.

9. A machine of the class described having, in combination, agrinding member, a support for a toothed cutter, means for imparting relative movement to said member and support to cause the cutter tobe brought into and out of contact with said member, means for rotating the cutter first forwardly and then backwardly while said cutter is out of contact with said grinding member, and means for limiting said backward movement.

10. A machine of the class described having, in combination, a grinding member, a support for a toothed cutter, means for imparting relative movement to said member and support to cause the cutter to be brought into and out of contact with said member, a pawl extending between two teeth of the cutter, and means for operating said pawl to cause it first to engage one tooth to rotate the cutter forwardlyand then to engage the other tooth to rotate it backwardly.

11. A machine of the class described having, in combination, a grinding member, a support for a toothed cutter, means for imparting relative movement to said member and support to cause the cutter to be brought into and out of contact with said member, a

pawl extending between. two teeth of the cutter, means for operating said pawl to cause it first to engage one tooth to rotate the cutter forwardly and then to en age the other tooth to rotate it backwar ly, and means for limiting said backward movement;

12. A machine of the class described having, in combination, a grinding member, a support for a toothed cutter, means for imparting relative movement to said member and support to cause the cutter to be brought into and out of contact with said member, a pawl for moving the cutter angularly while it is out of contact with said member to bring the teeth of said cutter successively into position to be operated upon, a second pawl arranged to support the particular tooth which is to be ground, and a spring acting upon said first-named pawl to cause it to move said particular tooth into firm contact with said second pawl prior to the grinding of said tooth.

13. A machine of the class described having, in'combination, a grinding member, a support for a toothed cutter, means for moving said support to bring said cutter into and out of contact with said grinding member, a pawl operated by said movement for moving said cutter angularly in a forward direction while it isvout of contact with said grinding member, a support for the tooth which is to be ground, and yielding means for causing said pawl to move said tooth backwardly into firm. contact with said support.

14. A machine of the class described having, in combination, a'grinding member, a support for a toothed cutter, mechanism for moving said support to present the teeth of said cutter one by one to said grinding member, means for operating said mechanism,

and automatic means for bringing said mechanism to rest when the last tooth has been ground.

15. A machine of the class described having, in combination, a grinding member, a support for a toothed cutter, mechanism for moving said support to present the teeth of said cutter one by one to said grinding member, means for operating said mechanism, and means controlled by the position of said-support for bringing said mechanism to rest when the last tooth has been ground.

16. A machine of the class described having, in combination, a grinding, member, a support for a toothed cutter, mechanism for moving said support to present the teeth of said cutter one by one to said grinding member, means including a belt for operating said mechanism, a shifter for controlling said belt, and means for operating said shifter when the last tooth has been ground.

17. A machine of the class described having, in combination, a grinding member, a support for a cutter, a shaft -rotation of which produces relative movement between said support and grinding member to cause said cutter to be brought into and out of contact with said grinding member, mechanism for rotating said shaft, and means for disconnecting said shaft from said mechanism.

18. A machine of the class described having, in combination, a grinding member, a support for a cutter, mechanism for swinging said support about an axis at one side of said grinding member to. bring saidcutter into and out of contact with said member, and means for rendering said mechanism inoperative whereby said support may be moved manually to facilitate adjustment of said grinding member with respect to said support.

19. A machine of the class described having, in combination, a rotatable grinding member, and a support mounted for oscil lation about an axis parallel to the axis of said member and provided with means for mounting a toothed cutter thereon in a plane transverse to' the directions of oscillation thereof, saidsupport being constructed and arranged with reference to the grinding member to carry the cutter into the plane of said axes during thegrinding operation.

20. A machine of the class described having, .in combination, a grinding member, a support having means for mounting a toothed cutter thereon and movable to present the teeth of the cutter one by one to the grinding member, power operating means for said member and support, a brake, and automatic means for disconnecting said member and support from the operating means and for applying the brake when the last tooth of the cutter has been ground. 1

21. A machine of the class described having, in combination, a grinding member, operating means therefor, a support for a toothed cutter, means connected with said operating means for imparting movement to said support to bring the cutter into and out of contact with the grinding member,

means for moving the cutter angularly while it is out of contact with said grind-' ing member, and automatic means for bringing said support and grinding member to rest when the last tooth has been ground.

22. A machine of the class described having, in combinatlon, a grindlng member, op

erating means therefor, a support fora cutter, and connections between the support and said operating means for imparting movement to the support to bring the cutter into and out of contact with the grinding member, said connections including a member slidably mounted for readily disconnecting said support from said operating means without interfering with the operation of the grinding member.

23. A machine of the class described having, in combination,,a grinding member, a support for a toothed cutter, mechanism for moving said support to present the teeth of said cutter one by one to said grinding member, means for operating said mechanism, and automatic means for disconnecting said mechanism from its operating means when the last tooth has been ground.

24. A machine of the class described having, in combination, a grinding member, a support for a cutter mounted for oscillatory movement about an axis extending transversely to the plane of the grinding face of said member'to carry the cutter into and out of contact with the grinding member, and means for moving the cutter angularly while it,is out of contact with said member comprising a lever pivotally mounted on said support, a pawl carried by said lever and arranged to effect rotation of the cutter, and cam means adjacent to the axis of said support for operating the lever on a movement of said support.

25. machine of the class described having, in combination, a grinding member, a support for a toothed cutter movable to carry the cutter into and out of engagement with said member, means operating in time relation to the movement of said support for advancing the cutter angularly to cause the different teeth of the series to be presented in succession to the grinding member,

and means for controlling the movement of 15 said support to prevent the first tooth of the series from being carried a second time into engagement with the grinding member after the last tooth of the series has been ground. .20

In testimony whereof I have signed my name to this specification in the presence of two subscribing Witnesses.-

ARTHUR ERNEST J ERRAM.

Witnesses:

FREDERICK WILLIAM \VORTH, KATHERINE PEATON. 

